C64 Reloaded

The C64 Reloaded is a new C64 mainboard - made in 2015. So what's new about the C64 reloaded? We're proud to say: Only very few things are new. We took the original Commodore schematics for mainboard 250466 and only did tiny surgical improvements to create a mainboard that is fully compatible with the original C64, but also has enhancements in a few spots that add to it's usability and reduce power consumption. Other than that, it's a C64, and we assume that you know exactly what that is - we therefore don't describe the C64 here, but the differencies and enhancements that we've made.

The power switch looks just like the original, but instead of two positions, it has three of them. In "down" position, the computer is switched off. In "middle" position, it's switched on. The "up" position will reset the machine, and automatically click back into the middle "on" position. This lets you use a reset button without the need to drill a hole into your case for an additional button.

Power conversion is probably the biggest change from the original C64 to our C64 Reloaded: Our design makes use of modern a DC-DC converter, which brings efficiency of the whole computer into the 21st century: While the original C64 requires a transformer-based power supply, which is very low-efficiency by it's design principle, our C64 Reloaded takes a 12V DC power source, so you can make use of a modern power supply that is compliant with the EuP-directive. This new, smart power design has a lot more reserves than the original C64: With up to 4 amps on the main 5V power rail, the C64 Reloaded can provide more than twice as much power than it's role model.

The original C64 can use a standard TV as a monitor, because it had a built-in TV modulator. The C64 Reloaded does not use this technology any more, because in the year 2015, TV sets with an interface for that kind of signal are not common any more. The C64 Reloaded has two connectors in the place of the TV modulator that let you make use of more common audio and video interfaces: An S-Video connector and a 3.5mm audio jack. These two connectors are mounted on a separate circuit board, which is mounted at an angle on the C64 Reloaded. This puts the two connectors in positions where the holes of the original C64 case can be used, and drilling or milling won't be required.

All ROMs of the C64 are united in a single EPROM chip, which not only reduces power consumption, but also gives some extra space for a second Kernal ROM and a second character set. Customers who own an EPROM programmer can create their own set of ROMs and switch between the two choices: The C64 Reloaded board gives the RESTORE key an additional meaning. The standard use of this key is to tap it once. On the C64 Reloaded, you switch between the two Kernal ROMs by holding down the RESTORE key for three seconds or more. Once again, this enhancement does not require any modifications on the original C64 case, so you don't have to damage such an original case. The EPROM of all C64 Reloaded boards are pre-programmed with two identical Kernal and character ROMs.

Finally, there is a true innovation under the hood of this new motherboard: The VSP-fix. VSP stands for "variable screen position" and it was first discovered in 1987. However, this programming trick does not work on all C64 computers. Some computers crash when this effect is used, and others work fine with it. For the C64 Reloaded, it's not a game of chances: All C64 Reloaded boards are VSP-safe. For an in-depth description of this feature, please read the technical article in our Wiki.

There are a few more technical details of the C64 Reloaded that may be of interest if you are a technical person. An in-depth description of jumpers, connectors and chip options can be found in our Wiki article about the C64 Reloaded, which also serves as online documentation.

Please keep in mind that some of the chips on this motherboard are used. Especially the two 6526-CIA chips, but also the video chip may have scratches. However, all boards have passed the same test procedure that was used by Commodore, and you have the iComp warranty on that. Please also note that we can't take your preferrence for any chip revision - the boards come pre-assembled and tested, and it would be too expensive and time-consuming to assemble the boards as orders come in.